Evaluating the virulence and longevity of non-woven fiber bands impregnated with Metarhizium anisopliae against the Asian longhorned beetle, Anoplophora glabripennis (Coleoptera: Cerambycidae)

Abstract

Fiber bands impregnated with entomopathogenic fungi (=fungal bands) provide an effective method for controlling the invasive Asian longhorned beetle, Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae). In this study we investigated the effective longevity of fungal bands for use against A. glabripennis, using several fungal strains. In the laboratory, adult beetles were immobilized on squares of fungal band impregnated with Metarhizium anisopliae (Metsch.) Sorokin isolate F 52 (ARSEF 7711) cultures to establish the median lethal concentration of 3.08 × 10 6 conidia/cm 2. During the summers of 2001–2004, bands impregnated with strains of M. anisopliae (2002–2004), Beauveria bassiana (2002), and Beauveria brongniartii (2001) were attached to trunks of trees in Queens, New York City to evaluate changes in densities of viable conidia over intervals of up to 119 days. The viability of conidia from bands was not associated with time in the field although total conidial density and density of viable conidia decreased with increasing time in the field. Bioassays conducted using samples of M. anisopliae F 52 bands in field sites in 2004 demonstrated that adult A. glabripennis died more quickly when exposed to higher concentrations of viable conidia. Although densities of viable conidia on bands decreased over time for all trials, they never decreased below the LC 50 estimates calculated in this study for M. anisopliae F 52. Our results demonstrate the pathogenicity of M. anisopliae F 52 fungal bands against A. glabripennis adults and show that the conidia from fungal bands can retain virulence in the field for at least 112 days.